I am looking into to connect my HF antenna to my transceiver and my SDR (the function of padadapter). I will use some relay (with enough isolation) to disconnect the SDR from the transceiver when transmitting. As when receiving both receivers needs to be combined maybe I can use this circuit. One thing I don't know is will it (or better how much) degrade the input signal (that insertion loss) from the antenna?
A Wilkinson is not very broadband. Your project sounds like you need to split a large frequency range, correct? In that case, the Wilkinson divider would not be a good design choice.
@BalticLab Thanks. I enjoyed your lesson. I have realized the relatief constraint, as you work with a resonant circuit. Most of the time I use the 20m band though. But yes, not ideal solution indeed. Before this I was thinking about a simple source follower with an hf fet, but I need to figure it out, as I don't want to degrade the signal from the antenna to this SDR receiver.... Any other ideas?
Even if your noise source is not so flat (say it's got some 1/f component or something) you could still measure the noise source un-filtered, then the noise source filtered and take the ratio between them to get the filter response, this is how we would measure optical filters with poor light sources that showed peaks and all sort of irregularities. As long as the power spectral density doesn't drift with time you'll be good but even then you could fight drift with averaging. This way you could get good nuff results without expensive noise sources. Edit: A minor problem with this is the ratio is usually super noisy outside of the noise bandwidth, the reason being if your noise drops too much you don't have resolution to observe how the filter is affecting it
The keys jingling sounded like it was simply downconverted. At first, I was thinking maybe that's what it was, that somehow either you goofed up your circuit, or it was a "hoax," lol. But, I'm glad you added the water pouring. I've never heard that before, but it's believable, at least to me! (Cuz of course I can't hear in the ultrasonic range!) Nice job! I wanted to build a downconverrtor, to listen to insects, birds, etc, but I figured I'd prolly like to also record what I heard. Then the circuit became too complicated, and I never got around to it! Oh, well. Good job with all the circuits. 👍👍
Breadboarded it! Had to use a 100uf, 100uf, 10uf, and 10uf in parallel to sub for the 220uf but had all the other components. This really works. I am thinking of using it for a guitar pickup system where I will mount a high quality JLI electret capsule in the body and combine with a piezo pickup. I may tweak the values a bit for better frequency response for guitar and add a volume pot, but thanks so much for this starting point! I am enjoying learning electronics
I thought I might try removing the resistor with circuit board nippers . do you think I could get away with that? (flush cut nippers) because using my irons, I'm afraid it'd goof it up.
You ptobably could get away with it but I would only recommend trying if you never want to undo the mod as this will likely damage the associated PCB traces
So we're you able to control only voltage with this without changing the current? I'd like to use this for an ion experiment in a vacuum, but my fear is that once the gas ignites the voltage will drop drastically to maintain the current setting when voltage is what I care about more than current.
Most of the time, I can't replicate the results I see on RU-vid, but since I have all the components, I'll give it a try. Anyway, great video. Thank you very much!
@@BalticLab Ive got a paper where thery went up to 0.1Thz and 0.48Thz, but no details. ''Frequency multiplier units based on SBDs, impact ionization avalanche transit-time devices (IMPATTs), tunneling transit time diodes (TUNNETT), and resonant tunneling diodes (RTDs).
@@ralfschooneveld3186 That would be 100 GHz to 480 GHz, no need to express that in THz. Though many research papers want to push THz, so they use stuff like "near THz" to push keywords.
how about a project that is unique, instead of something dozens have already done, and the information is available for free on NOAAs website? or is this some kind of product marketing type video?
Thanks for your comment. Especially for DIY, electronics (and other science related) topics, it'd be hard for creators to post highly original content that hasn't appeared anywhere else in some shape or form. And I think it's perfectly fine to post ones own version as every creator has a different take on things, a different presentation style and focuses on different aspects. Also, topics such as this are easily researchable if the person is aware of what to look for. Many people do not know that they can receive weather satellite images themselves. So of course this is interesting for people who never stumbled across this before. That others have done something similar, or highly adjacent, is something I frequently mention in my videos because - unlike other creators - I actively encourage viewers to look around other channels. People like different presentation styles and formats. So if someone finds a different creator after watching this video, who better matches their prefered style, I am happy for them. From my research I am the only one showing a very simple V-dipole directly into a RTL-SDR on a Windows PC. So while the topic isn't new, this is a differen take on things.
Great video. I'm interested in replicating your power supply for use in an electrospinning device that requires between 10 - 30 kV. However, most commercial power supplies (such as the SKE EF020) limit current to around < 1 mA. Is it possible to reduce the current in your design whilst maintaining high voltage?
You can limit the current to 1 mA by adding a current limiting resistor in series. Just make sure its appropriately rated for the voltage and the dissipated power.
Hi! That's probably not a good method for measuring flicker noise as thermal noise us the reference, yet all test equipment will bring it's own flicker noise issues with it.
Is this under black light or is this emitting light with hydrogen peroxide?? So pretty! I mixed rhodamine b and fleuroscine with rubbing alcohol but never hydrogen peroxide..
It's an aqueous solution with NaOH and hydrogen peroxide. Basically the standard luminol recipe except with multiple, unstirred fluorescent dyes at once.
@@BalticLab can you write a concentrations of the solutions, please? I'm looking for a colorful experiments for kids and I will be very grateful if you send an experiment setup
I already showed a Ku band transmitter (ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-jWDu2BkVWnw.htmlsi=5riGTQkg_tibKkyl) but a teardown of the BUC would indeed be a great idea!
Those bubbles slow down the etching a lot. If an aquarium air pump is added to mix the etchant the process takes minutes. I've built a flat tank from acrylic for this purpose, it reduces the amount of liquid needed and placed the outlet of the air compressor at the bottom. The liquid gets stirred extremely well.
Nice setup, these Chinese laser tubes are cheap but dangerous due to their highvoltage wiring and safetyless HV power supply. 30kV with no proper HV shielded cable and a return path to the power supply housing is a deadly combination. Water ports are fragile. Life time is abit over 1 year then to the trash. Beam has usually side lobes and not pure gaussian, so this thing good for average quality production in job shops.
Good to know. That Wilkinson video apparently has quite some popularity I was invited to give a lecture on Wilkinson design at a local university recently after many students referenced my videos in their lab reports. 😄
Very interesting video! Not sure if this would be something you are interested in or have the time for but I would really appreciate much simpler and in detail versions of these videos. An "explain me like I'm five" version so to speak. Questions to answer could be: What actually is a LNB? What does it do? How does a horn antenna/waveguide work? How does the amplification work? And how does the signal look like that is being amplified? What does K-Band mean? There are a lot of channels explaining the basics of electronics but I think application-oriented explanations would make these theoretical lessons much more interesting. I know your channel is probably for viewers with more knowledge about electronics. So it's just a suggestion :)
Actually a great idea. With the depth and complexity of RF I will have to think about how to best do that, whether it's gonna be a 1 hour video or 10 segmented videos. Maybe a combination, a teardown vid followed by derrivatives of interesting features in the design.
Are the 38khz sidebands AM modulated? (prior to FM modulation of the whole signal for transmission) If so, that's kind of funny that FM stereo contains an AM component.
It's double sideband modulation for the 38 kHz subcarrier. This modulation type stacking actually happens a lot. FM subcarrier modulated onto an AM signal is used in aviation VOR stations for instance.
Interesting IC. It replaces the dielectric oscillator, mixer, amplifier, voltage comparator and 22kHz detector. 20 years ago this would all be discrete components.
Yes indeed. Actually, one of my very first videos was an old C-band LNB teardown video, huge difference: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-DkURL4mETT4.html
